Diego Costa looked on as Atletico Madrid allowed themselves to keep pace with Barcelona at the top of La Liga with a 2-0 win over Sevilla.
Costa is back with Atletico after Chelsea agreed to grant his wish to return, although the Spanish club's transfer ban means he will have a watching brief until January.
He was able to enjoy what he saw on Saturday, as his new club took further advantage of Real Madrid's early-season indifference and moved six points clear of their city rivals.
They are also just a point behind Barcelona, albeit having played a game more.
Yannick Carrasco opened the scoring a minute after an even first half which saw both sides hit the woodwork through Filipe Luis and Pablo Sarabia.
Carrasco was able to break clean through on the Sevilla goal, round Sergio Rico and tuck in.
Antoine Griezmann made it two, slotted in on the left of the area by Luis and drilling a terrific effort across Rico to settle it.
Atletico have now won both their two games at their new Wanda Metropolitano home.